The present invention relates to a printing technology and, more particularly, to a combination printing method for IMD (In-Mold Decoration) hot press and injection molding application.
Conventional IMD (In-Mold Decoration) printing methods include screen-printing, spray-painting, and direct injection-molding. Few IMD printing providers accept the method of screen-printing because the printing speed of the method of screen-printing is slow (about 2000 runs per hour), and not suitable for rapid output. The method of spray-printing is complicated. After the application of each color of paint and before the application of a nest color of paint, the workpiece must be dried by baking or with the radiation of a UV lamp. The method of direct injection-molding is the most popularly accepted printing method. According to this direct injection-molding printing method, the desired color pigment is added to the material before IMD hot pressing and injection molding. However, because only one single color is provided each time, this method cannot produce a versatile color pattern.
The present invention has been accomplished to provide a combination printing for IMD (In-Mold Decoration) hot press and injection molding application, which eliminates the drawbacks of the prior art printing methods. According to the present invention, the combination printing method comprises the steps of (1) offset printing; (2) color pattern offset printing; (3) primary screen printing; (4) primary baking; (5) secondary screen printing; (6) secondary baking; (7) hot pressing; (8) shape rolling; and (9) injection-molding. By means of the performance of the aforesaid steps and the application of specially prepared compound ink, rapid printing output with versatile printing pattern is achieved.